1/* @(#)e_scalb.c 5.1 93/09/24 */ 2/* 3 * ==================================================== 4 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. 5 * 6 * Developed at SunPro, a Sun Microsystems, Inc. business. 7 * Permission to use, copy, modify, and distribute this 8 * software is freely granted, provided that this notice 9 * is preserved. 10 * ==================================================== 11 */ 12 13#if defined(LIBM_SCCS) && !defined(lint) 14static char rcsid[] = "$NetBSD: e_scalb.c,v 1.6 1995/05/10 20:46:09 jtc Exp $"; 15#endif 16 17/* 18 * __ieee754_scalb(x, fn) is provide for 19 * passing various standard test suite. One 20 * should use scalbn() instead. 21 */ 22 23#include <fenv.h> 24#include "math.h" 25#include "math_private.h" 26 27#ifdef _SCALB_INT 28#ifdef __STDC__ 29 double __ieee754_scalb(double x, int fn) 30#else 31 double __ieee754_scalb(x,fn) 32 double x; int fn; 33#endif 34#else 35#ifdef __STDC__ 36 double __ieee754_scalb(double x, double fn) 37#else 38 double __ieee754_scalb(x,fn) 39 double x, fn; 40#endif 41#endif 42{ 43#ifdef _SCALB_INT 44 return __scalbn(x,fn); 45#else 46 if (__isnan(x)||__isnan(fn)) return x*fn; 47 if (!__finite(fn)) { 48 if(fn>0.0) return x*fn; 49 else if (x == 0) 50 return x; 51 else if (!__finite (x)) 52 { 53# ifdef FE_INVALID 54 feraiseexcept (FE_INVALID); 55# endif 56 return __nan (""); 57 } 58 else return x/(-fn); 59 } 60 if (__rint(fn)!=fn) 61 { 62# ifdef FE_INVALID 63 feraiseexcept (FE_INVALID); 64# endif 65 return __nan (""); 66 } 67 if ( fn > 65000.0) return __scalbn(x, 65000); 68 if (-fn > 65000.0) return __scalbn(x,-65000); 69 return __scalbn(x,(int)fn); 70#endif 71} 72